diff --git a/Algebraic_foundations/examples/Algebraic_foundations/algebraic_structure_dispatch.cpp b/Algebraic_foundations/examples/Algebraic_foundations/algebraic_structure_dispatch.cpp
index e3292e53c87..18d46b5c4f4 100644
--- a/Algebraic_foundations/examples/Algebraic_foundations/algebraic_structure_dispatch.cpp
+++ b/Algebraic_foundations/examples/Algebraic_foundations/algebraic_structure_dispatch.cpp
@@ -1,5 +1,6 @@
 #include <CGAL/IO/io.h>
 #include <CGAL/Algebraic_structure_traits.h>
+#include <CGAL/number_type_basic.h>
 
 template< typename NT > NT unit_part(const NT& x);
 template< typename NT > 
diff --git a/Algebraic_foundations/examples/Algebraic_foundations/integralize.cpp b/Algebraic_foundations/examples/Algebraic_foundations/integralize.cpp
index c3f2dbe9043..6181dbf5040 100644
--- a/Algebraic_foundations/examples/Algebraic_foundations/integralize.cpp
+++ b/Algebraic_foundations/examples/Algebraic_foundations/integralize.cpp
@@ -1,6 +1,7 @@
 #include <CGAL/Fraction_traits.h>
 #include <CGAL/IO/io.h>
 #include <vector>
+#include <CGAL/number_utils.h>
 
 template <class Fraction>
 std::vector<typename CGAL::Fraction_traits<Fraction>::Numerator_type >